/*
 * Copyright (C) the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.derquinse.bocas;

import static com.google.common.base.Preconditions.checkNotNull;
import net.derquinse.common.base.NotInstantiable;

import com.google.common.io.ByteSource;

/**
 * Package private internal utility functions.
 */
final class InternalUtils extends NotInstantiable {
	/** Not instantiable. */
	private InternalUtils() {
	}

	/** Converts an exception thrown during cache loading. */
	static BocasException convertCacheException(Throwable t) {
		Throwable cause = t.getCause();
		if (cause != null) {
			return new BocasException(cause);
		} else {
			return new BocasException(t);
		}
	}

	/** Checks the value to put has been provided. */
	static <T extends ByteSource> T checkValue(T value) {
		return checkNotNull(value, "The value to add can't be null");
	}

	/** Checks the transformed value to put has been provided. */
	static <T extends ByteSource> T checkTransformedValue(T value) {
		return checkNotNull(value, "The transformed value to add can't be null");
	}
}
